As is known, for example, from U.S. Pat. No. 4,413,724 or EP 1 275 603 A1, such a device, based on the continuous displacement capacity of the carriage in both directions, allows a rapid and finely tuned adaptation of the buffer capacity as a function of the conditions at the entry station and at the exit station and thus it makes it possible, for example, to dynamically couple two machines that can be operated with different outputs. It is characteristic here that all the objects that enter into the entry station or are removed from the exit station pass through the entire conveying section with variable length in each operating state, where the conveying section thus has simultaneously a transport and also a storage function. The positioning or the movement of the carriage is achieved automatically with the two drive devices for the conveying means, and the objects can remain on the conveying means during the transport from the entry station to the exit station without excess advance.
However, the deficient lateral guidance for the objects is a disadvantage, because the objects stand freely on the conveying means, particularly in areas of deflections. The known dynamic storage devices are consequently not suitable for the rapid transport of objects with low resistance to tipping, for example, empty plastic bottles.
In addition, the flexible conveying means of the known devices, which are formed by link chains, are received substantially with sliding motion in stationary guide rails, which results in a high degree of wear. To further complicate the situation, in EP 1 275 603, in the case of a spiral-shaped design of the variable conveying section, strong traction forces directed toward the interior of the arc of the link chains occur. In this known device, the link chain also must engage in the area of the deflections of the carriage with the stationary guide rails, against the tractions which act towards the interior of the arc. The presented solutions to lift the link chain by means of a rotating deflection disk or by lowering the guide element of the interior of the arc are not suitable for a practical continuous use with high conveyance output.